Combine 4110 channels and devices to achieve greater output current

[dblasco]

Hi,

I have two NI PXI-4110 to power one device that needs to be powered as follows:

5V with 3.3A

-15V with low current

My idea is to use the channels 0 and 1 of the two power supplies (4 channels in total) to power the 5V part and the channel 2 for the -15V.

Is it possible to connect these 4 channels in parallel (each one provides 1A) to obtain up to 4A? If it is the case, how should I do the connection (specially regarding to the connection between the two different devices, should I include a resistor between them?)

Thank you!

[ChristophersonJ]

HI @dblasco, 

Unfortunately we don't recommend combining the outputs of multiple devices together. 

combining channels on a single device is alright, but once you combine multiple devices together you cause the respective control loops to fight against each other. 

This can cause a lot of instability in your outputs. 

We do have some guidance on combining output channels on a single device: 

http://zone.ni.com/reference/en-XX/help/370736R-01/ni_dc_power_supplies_help/4110_output_connections/

^Most every Power Supply and SMU has a similar article in the help. 

I know this isn't the answer that you were hoping for, but you're not going to be able to get 5V and 3.3A with the 4110 (obviously it's the 3.3A that's the issue). 

We do have some other power supplies and SMUs that can natively provide that however. 

The PXIe-4113 can do 10V and 6A for instance. 

The 4110 can do -15V and low current (assuming that low current is <1A)

I hope this is helpful, even if it isn't satisfying

Best Regards,

ChristophersonJ

[dblasco]

Dear ChristophersonJ,

thank you for your answer. I understand it is the not recommendable.

However, I found another possibility. I got two extra 4110 supplies. My idea would be the to use the channel 0 of each power supply connecting them in parallel to achieve up to 4A.

Would this be a better approach?

Thank you

[ChristophersonJ]

Hey @dblasco, 

again, for the reasons stated above, we don't recommend combining the outputs of multiple devices.

Whether in series for more voltage or in parallel for more current. 

You run the risk of destabilizing your outputs, possibly damaging your modules or the DUT they're connected to. 

Best Regards

ChristophersonJ